Each of the answers is in its own text caption. They are evenly spaced ... if your answers have only one line. But the captions expand automatically if you have multiple lines, whereas the space between the captions doesn't change, which causes your issue.
My work flow is this:
This work flow will also provide enough space in case you use Shuffle answers.
If you perhaps are using CP6, the answers seem to be grouped in another "rectangle", then you'll have first to make that area bigger using the Transform accordion, unchecking the Constrain proportions. A very annoying extra step... not the only one that is frustrating me.